The square knot serves to hold a folded sail when not in use. It’s important not to tie this knot wrong, for if a strand passes over or under incorrectly, the sail’s sure to unfurl!
STEP 1
Make a bight with a rope. With another rope, wrap it first from beneath, then go above, then slide it under the two strands of the bight.
Finish by passing it over and under.
STEP 3
Essential: no matter what, if the two strands come out above one side, then they must come out underneath on the other side.
To tighten the knot, pull the four strands at the same time.
